1. Technical Field
The present disclosure relates to washers, and particularly to washers for hinge assemblies for foldable electronic devices, such as mobile phones and portable computers.
2. Description of Related Art
Presently, perhaps the most popular portable electronic device in the marketplace is the foldable mobile phone, which generally includes a cover section and a body section. The cover section and the body section are rotatably interconnected through a hinge assembly, for switching the mobile phone between an in-use position and a closed position.
A typical hinge assembly used in small foldable electronic devices includes a shaft, a cam, a follower, a spring, a sleeve and an E-shape washer. The sleeve has a partially-closed end and an open end. The cam and the spring are placed on the shaft, and are received in the sleeve. The E-shape washer is locked at one end of the shaft, and resists the outside of the partially-closed end of the sleeve. The follower is partially received in the sleeve from the open end, and is secured on the other end of the shaft.
Accordingly, the hinge assembly is completely assembled.
However, when the sleeve rotates relative to the shaft, a large friction torque is produced between the E-shape washer and the sleeve. This will reduce mechanical efficiency. In addition, when the E-shape washer is locked on the shaft, a point contact is formed therebetween. The contact area is small, thus more abrasion may be produced.
Therefore, there is room for improvement within the art.